Rebar Placement ???'s

[icthrooyou]

Hey folks!

For my new home, I'm pouring 8" thick by 8' tall basement walls. I live in a rural section of our county and am not governed by a local building code. My plans only specified two rows of #4 rebar in the bottom of the footings and none for the walls. However, I feel it would be wise to reinforce the walls as well.

First, I am ready to pour the footings later this week and have laid in two rows of #4 rebar in chairs at the bottom. Do I also need to place rebar at the top as well?

Second, what size rebar and placement configuration should I use for the stem walls? I will have vertical rebar coming out of the footing to tie into the wall and a keyway cast into the top of the footing as well. I've seen several people here comment that verticals should be placed 4' OC. Correct? Should I also have horizontals and if so, how should they be placed?

Also wondering about whether or not to pay for the additional $7/yd for fiber reinforcing? What would be a good way to go here? The house is listed as a 1-1/2 story. Here are some pics of the house & layout:
http://www.creations4christ.com/wolfecreek/newhouse1.jpg
http://www.creations4christ.com/wolfecreek/newhouse2.jpg
http://www.creations4christ.com/wolfecreek/newhouse3.jpg

Thanks so much for your help!! This forum is AWESOME!!
Take Care and God Bless!!

\o/ Paul

[Rich]

I wouldn't worry about the fiber mesh - with the rebar it's pretty much redundant. I would probably make a grid 4' o.c. horizontal and vertical out of #4 bar.

[Tom R]

icthrooyou,

That is one sharp house!!

[icthrooyou]

Thanks once again Rich! Just to be sure, I should have one run of horizontals at both top and bottom in addition to the verticals 4ft OC?? Or should I also add a MIDDLE run of horizontals to make 4'x4' squares?? Don't mean to be dense...

Hey thanks Tom! Yeah, we looked at houseplans until we were numb and they all started looking exactly the same (I think the numbness came first...or maybe the other way around? :shock: ). Then we saw some designs here and there in our search that had a definite "flair" about them. We began to notice they were all from the same design company called Drummond Designs. Oddly enough, they're located in Drummondville, Quebec. We found them at www.coolhouseplans.com Their whole approach to design seemed to totally stand out from the rest of the pack. We found this particular house and absolutely fell in love with it! I can't WAIT to get it done!!

Thanks again Rich! This forum is yet more proof that some of the greatest things in life ARE actually free!! :D

[Rich]

Yes.. 4' squares. I appreciate the compliments. as I'm sure many of the other members do too.

[RobBase]

icthrooyou, one thing you didn't mention is how far will your basement walls be above finish grade. This is needed to determine the maximum unbalanced backfill height which determines the reinforcing required for your walls.

Maximum unbalanced backfill height is the height from the basement floor slab to the finished grade on the outside of the basement. According to generic building codes, for a 8" thick wall that has a 6' or less MUBH (abbreviated) no rebar at all is required. However, if you go to a 7' or more MUBH, then you should have #4 rebars @ 12" o.c. vertically and a #4 12" from the top of the wall and another #4 at the midheight of the wall.

Fibermesh is generally only used for slabs and even then it is not a substitue for wire mesh. In my opinion it is rather worthless.

[icthrooyou]

Hmm.... That seems like a big jump in reinforcement to go from NONE at 6 ft MUBH to 12" OC at 7 or 8 foot... Is that a BOCA code reference or a local code that is dependent on a unique soil composition and/or excess hydrostatic pressures?

Mine are going to be backfilled to around 7ft for the most part. Some will be less because of a daylight basement on the right and rear elevations.

Oh yeah, do I need to reinforce the TOP of the footings?? I laid 2 rows of #4 in the bottom, but what about the top?? Pouring on Friday...

Thanks for the info!

\o/ Paul

[RobBase]

The code that rebar spec came from is the HUD Prescriptive Guide to ICF construction. As in insulated concrete forms. That is the type of house I'm building and I just happened to have that on the laptop we have in our trailer. I also have a copy of the IBC at home and I believe that their rebar specs are the same since a concrete wall is a concrete wall whether it's ICF or not (as long as it's not a waffle or grid type).

I don't really buy or should I say, go along with the part where they claim no rebar at all is needed......it might be sound engineering, but I'd rather be safe than sorry. Since your walls are right at the limit of backfill height, I again think its better to be safe than sorry. Just imagine the amount of sleep you'll get at night knowing that you don't have to worry about a cracked basement wall.

As far as your footing, you do not need rebar at the top of the footing. 2 rebars at the bottom 2-3" above the dirt is fine......3 would be better.

Almost forgot, the rebar chart I got the placement from has 3 levels of dirt consideration, 30 pcf, 45 pcf, & 60 pcf (pounds per cubic foot). I interpolated between the 2 worst cases.

[icthrooyou]

Gotcha!

Thanks Rob!

\o/ Paul